nhk world's political commentator nakajima joins us. tell us how obama won a second term? >> for a start, he is the incumbent president that puts him in a position of power. all through u.s. history incumbents have usually had the advanta advantage. obama campaigned on his achievements. health care reform, ended the war in iraq, decided to pull back in afghanistan and killed osama bin laden. he took the lead in managing the disaster. that was a winning move. obama also found support among the middle class, the biggest group of american voters. he said he would end tax cuts for the wealthy and give everyone access to health care. >> i guess the big question is what will the president's next four years look like? >> along with his main domestic challenge, the economy, he'll also have to face challenges abroad. iran and north korea are two nations his administration will need to address. he'll continue to pressure them to stop their nuclear development. but at the same time president barack obama will have to be very careful to avoid military conflicts. he knows very well tha